summaryrefslogtreecommitdiff
path: root/lib/crypto/chacha.c
diff options
context:
space:
mode:
Diffstat (limited to 'lib/crypto/chacha.c')
-rw-r--r--lib/crypto/chacha.c40
1 files changed, 20 insertions, 20 deletions
diff --git a/lib/crypto/chacha.c b/lib/crypto/chacha.c
index 3cdda3b5ee06..ced87dd31a97 100644
--- a/lib/crypto/chacha.c
+++ b/lib/crypto/chacha.c
@@ -13,8 +13,9 @@
#include <linux/unaligned.h>
#include <crypto/chacha.h>
-static void chacha_permute(u32 *x, int nrounds)
+static void chacha_permute(struct chacha_state *state, int nrounds)
{
+ u32 *x = state->x;
int i;
/* whitelist the allowed round counts */
@@ -65,34 +66,34 @@ static void chacha_permute(u32 *x, int nrounds)
/**
* chacha_block_generic - generate one keystream block and increment block counter
- * @state: input state matrix (16 32-bit words)
- * @stream: output keystream block (64 bytes)
+ * @state: input state matrix
+ * @out: output keystream block
* @nrounds: number of rounds (20 or 12; 20 is recommended)
*
* This is the ChaCha core, a function from 64-byte strings to 64-byte strings.
* The caller has already converted the endianness of the input. This function
* also handles incrementing the block counter in the input matrix.
*/
-void chacha_block_generic(u32 *state, u8 *stream, int nrounds)
+void chacha_block_generic(struct chacha_state *state,
+ u8 out[CHACHA_BLOCK_SIZE], int nrounds)
{
- u32 x[16];
+ struct chacha_state permuted_state = *state;
int i;
- memcpy(x, state, 64);
+ chacha_permute(&permuted_state, nrounds);
- chacha_permute(x, nrounds);
+ for (i = 0; i < ARRAY_SIZE(state->x); i++)
+ put_unaligned_le32(permuted_state.x[i] + state->x[i],
+ &out[i * sizeof(u32)]);
- for (i = 0; i < ARRAY_SIZE(x); i++)
- put_unaligned_le32(x[i] + state[i], &stream[i * sizeof(u32)]);
-
- state[12]++;
+ state->x[12]++;
}
EXPORT_SYMBOL(chacha_block_generic);
/**
* hchacha_block_generic - abbreviated ChaCha core, for XChaCha
- * @state: input state matrix (16 32-bit words)
- * @stream: output (8 32-bit words)
+ * @state: input state matrix
+ * @out: the output words
* @nrounds: number of rounds (20 or 12; 20 is recommended)
*
* HChaCha is the ChaCha equivalent of HSalsa and is an intermediate step
@@ -100,15 +101,14 @@ EXPORT_SYMBOL(chacha_block_generic);
* skips the final addition of the initial state, and outputs only certain words
* of the state. It should not be used for streaming directly.
*/
-void hchacha_block_generic(const u32 *state, u32 *stream, int nrounds)
+void hchacha_block_generic(const struct chacha_state *state,
+ u32 out[HCHACHA_OUT_WORDS], int nrounds)
{
- u32 x[16];
-
- memcpy(x, state, 64);
+ struct chacha_state permuted_state = *state;
- chacha_permute(x, nrounds);
+ chacha_permute(&permuted_state, nrounds);
- memcpy(&stream[0], &x[0], 16);
- memcpy(&stream[4], &x[12], 16);
+ memcpy(&out[0], &permuted_state.x[0], 16);
+ memcpy(&out[4], &permuted_state.x[12], 16);
}
EXPORT_SYMBOL(hchacha_block_generic);